Four years almost to the hour from those heady days of popular adoration, change did indeed come to America, as Barack Obama swept to a victory over Mitt Romney at the head of a new progressive coalition of women, minorities and the young.

In the process, Mr Obama may have ushered in a once-in-a-generation shift in the American political landscape, changing the face of the nation.

Mr Obama won the Electoral College by 100 votes, but the popular vote by just one per cent.

This is the raw mathematics of a country that cannot agree to do what needs to be done – on debt, on immigration, on education – if it wants to remain competitive in a global world.

But the paradox of the 2012 US election was that despite the numerical proximity of the vote Mr Obama's open-minded liberal coalition may now have taken a permanent stranglehold on the US political map.

And in their inclusive fervour they have left half the country locked outside the door.

Study a map of Tuesday's vote plotted geographically – with the two parties coloured red and blue – and it is clear that outside the cities and the coasts of this vast country, America still has a conservative heart.

That heart will feel angry and dispirited by this defeat. In victory, Mr Obama tried to sound magnanimous, but even as he waxed lyrical about a new vision for an inclusive polity, he rammed the defeat down the throats of the vanquished.

"It doesn't matter whether you're black or white, or Hispanic or Asian, or Native American, or young or old, or rich or poor, able, disabled, gay or straight – you can make it here in America if you're willing to try," he said.

Deliberately or not, there was little space, it seemed, in that long list for ordinary, hard-working God-fearing Americans – many white, many living in rural areas – who still make up a vast swathe of the country but are being eclipsed by a new demographic reality.

It is a reality born by the facts: Hispanic voters comprised 10 per cent of the electorate. Mr Obama won seven out of 10 of their votes. The president also won 93 per cent of the black vote, and more than 70 per cent of Asian voters. He led by 12 points over Mr Romney among women.

Among young voters, he secured two thirds of the preferences of those aged between 18 and 29. They are almost a fifth of the electorate.

For the first time last year in America more babies were born to non-white parents that to whites, a trend which explains why the Republican party can no longer afford to ignore Hispanic voters, even though this campaign, with all its hostility towards immigrants, seemed so determined to alienate them.

The shift saw Mr Obama holding old southern states such as Virginia, which he had won in 2008 on the back of a euphoric wave of support which some put down to a fluke.

But as African-Americans and students turned out in droves to take the state again, it was clear that the race had heralded a new, more permanent, drawing of the political map. Mr Obama's coalition represents the future of America: a younger, browner, more godless and liberal America whose taxes must also pay for the retirement funds of the older, white evangelical Christian Americans that they are supplanting.

The scale of Tuesday's Republican defeat portends a new electoral reality. Looking forward to 2016, analysis by the Washington Post shows that such is the seismic nature of the demographic shift against the Republicans that the maximum number of Electoral College votes the party could win may be as low as 292.

That is a margin, scarcely more than the 270 needed to win, that must deeply alarm the party and spur them to adopt a more inclusive agenda or risk facing many more years in the electoral wilderness.

Whether that comes to pass will depend on Republicans showing that innate capacity for reinvention that has always been the dynamo of America. That capacity will be sorely tested over the coming four years, but an opportunity does lie ahead.

If nothing else, this crushing defeat should force a rethink by Republicans who must now see that the Reagan-era coalition of fiscal conservatives and evangelical Christians no longer holds water. They have now lost five of the last six popular votes in US elections. They must decide to broaden their appeal and – at the very least – re-engage with the Latino populations of Texas, Florida and Arizona or face electoral oblivion.

It is depressing to think that 82 per cent of all non-whites in America voted for one political party, regardless of their age, economic status and social views.

At a time when the US has elected its first openly gay senator – Tammy Baldwin from Wisconsin – and when polls show half of America now believes that gay men and women deserve to love their partners with the same rights as straight couples, it is the moment to rethink the bounds of tolerance.

When Mr Obama wins the votes of unmarried women by 38 points, it speaks to an abject failure of the Republican Party to rein in a vocal minority who represent the extreme fringes of what is considered acceptable to the majority of Americans.

But necessity can be the mother of invention. This could bring Republicans face to face with their mortality.

A starting point for change might be immigration. America, a country founded by immigrants, desperately needs to fix an immigration policy that indiscriminately excludes talent that now finds homes elsewhere – in China, India and South America.

Everyone knows this must be done, but Congress has been deadlocked on any deal as both sides clung to their electoral dogmas these last two years. Now a window for change has opened. It could open too on securing a deal to pay down America's debt and on putting in place environmental policies worthy of the "can do" spirit of a country that put a man on the Moon and a television in every home to watch him walk upon it.

It is to be hoped that Congressional Republicans, now thwarted in their singular aim of denying Mr Obama a second term, will face up to reality and do what they were sent to Washington to do – pass legislation, build compromises and put America onto an affordable fiscal track.

It is also to be hoped that the unions and vested interests on the Left accept that America's coffers are not bottomless. And that Mr Obama has the courage to tell them so.